Network Function Virtualization (NFV) is a network architecture concept that uses virtualization related technologies to virtualize network node functionalities into virtual building blocks that may be connected, or chained, together to create communication services. NFV aims to transform the traditional telecommunication operator networks by evolving standard Information Technology virtualization techniques to consolidate network equipment types onto industry standard high volume services, switches and storage, which could be located in a variety of points of presence including Data Centers, network nodes and in end user premises. It is also indicated that an important part of controlling the NFV environment should be done through automation network management and orchestration.
Network functions such as firewall, load balancer, WAN optimizer, etc. have conventionally been deployed as specialized hardware servers in both network operators' networks and data center networks, as the building blocks of the network services. With virtualization and NFV it is possible to move or extend the existing network function into a data center.
Numerous virtualization requirements have been discussed with respect to NFV including: portability, performance, elasticity, resiliency, security and service continuity. Performance and resiliency are considered important requirements when virtualizing telecom network functions such as Mobile Core Network functions. IMS functions, Mobile base station functions, Content Delivery Networks (CDN) functions, Home Environment functions, and Fixed Access Network functions. Migrating these telecom functions to a virtualized environment involves moving the control plane, data plane and service network into a cloud based network and using cloud based protocol to control the data plane. Service continuity, network security, service availability, resiliency in both control plane and data plane must be ensured at this migration.
High Availability (HA) can be achieved by eliminating any Single Points of Failure (SPOF) by creating a redundancy of resources. HA is ensured by the availability management functions at the platform, middleware, and application levels. Normally, HA is achieved with redundant infrastructure by including enough excess capacity in the design to accommodate a performance decline, that a group of network function instances providing the same functional works as a network function cluster, which provides failover and increased availability of applications, or parallel calculating power in case of high-performance computing clusters as in supercomputing.
There are several existing HA solutions, in which a cluster based High Availability solution is supported. A failover capability is achieved through redundancy across the multiple connected machines in the cluster, each with independent failure states. In the cloud environment, where the applications are running in virtualized execution environments (e.g. as a virtual machine), a hypervisor-based solution may also provide High Availability capability. Such solutions can provide continuous availability for applications in the event of server failures by creating a live shadow instance of a virtual machine that is always up-to-date with the primary VM. It monitors the hosts and VMs to detect any hardware and guest operating system failures. In the event of an outage, it can automatically trigger a failover to ensure zero downtime and prevent data loss. After the failover, a new virtual machine will be automatically created as the standby.
Today the usage of personal devices, e.g. smartphones and tablets, for internet service traffic, telecom specific service access, and accessing the corporate network, has increased significantly. At the same time, telecom operators are under pressure to accommodate the increased service traffic in a fine-grained manner. Services provided by telecom network must be done in an environment of increased security, compliance, and auditing requirements, along with traffic load may be changed dramatically overtime. Providing self-service provisioning in telecom cloud requires elastic scaling of the VNF based on the dynamic service traffic load and resource management e.g. computing, storage, and networking.